Many lasers allow you to disable the self-leveling function and use the tool to project sloped lines and layout.
All of the instruments come with some kind of case and a means of holding the units up off the ground so that you can see where the down beam hits the surface. The larger units – the Johnson, the PLS, and the Topcon LC-4X – have legs that can be adjusted slightly up and down to level the device. The legs on the Johnson model can be removed or folded out of the way for storage. Bosch's laser requires no base because the beams that cross to form the down point are beyond the edge of the housing. Other tools include an accessory base that clips or screws to the bottom of the unit. Hilti's base contains magnets that hold it against floor track to make it easier to plumb light-gauge steel walls. The others have magnets on the back so you can support the tool by sticking it to a steel stud or post.
Hilti's laser comes with both a camera-style tripod and a bracket for hanging it from the wall or strapping it to a pipe or post. The brackets for two of the tools contain mechanisms for adjusting the elevation: Bosch's sits on the floor or bolts to a tripod, and PLS's hangs from the wall or clips to the track of a suspended ceiling.
All the tools can be mounted on tripods. The larger models (Johnson, PLS, and Topcon LC-4X) accept the 5/8-inch x 11 fittings used on standard construction tripods. If you don't already own a construction tripod, it's worth investing in one for outside work, because they're stable on uneven ground. If the tool is designed to project sloped lines, you can get those lines by putting it on a video tripod and tilting the head to the desired angle. The Agatec, Hilti, Leica, and Topcon LC-2 models are tapped to fit the 1/4-inch x 20 fittings on camera and video tripods but can be adapted to construction tripods. The Bosch and the Spectra Precision will fit either type of tripod without an adapter.
Many lasers include special targets or glasses that make it easier to see the beams in bright ambient lighting. You wouldn't think batteries would matter, but tools consume more power when they're projecting more than one line. If you're a heavy user you'll go through a lot of batteries, so you might want to consider rechargeables. The PLS laser includes a charger, an AC adapter, and four rechargeable batteries. The Johnson includes a pair of power packs – one is rechargeable and the other takes AA batteries.What to Buy?
There is no right answer to this question. It's more a matter of the features you need and the amount you can afford to spend. Even a bargain-basement model will be an improvement over older methods of leveling and laying out. If you do a mix of interior and exterior projects, it's best to get a pulsing tool and receiver. If your focus is exclusively on interior finish, you can save some money by forgoing the receiver. Stair builders and tile setters would be well-advised to seek models that can be placed on a video tripod and tilted to produce sloped lines and diagonal layout.
After putting these lasers in the hands of five different carpenters on multiple remodeling projects, we came up with several favorites.
At the upper end (in terms of price and features) are the Bosch and the PLS. Both project three 360-degree planes of light – two vertical and one horizontal. The vertical planes cross each other at 90 degrees and run all the way across the floor, walls, and ceiling. I have a hard time thinking of any kind of layout you can't do with these tools. The Bosch tool levels more quickly because it has a pendulum; the PLS projects a steadier line because it's leveled by servo motors.
Our midlevel favorites are the Spectra Precision and the Leica Lino. If I had to choose just one laser for my company, it would be one of these. The Spectra Precision is a combination of a cross-line laser and a 5-point laser (6-point if you count where the lines cross). The cross lines go out the front and the points go up, down, left, right, and back. The horizontal lines fan to less than 180 degrees, but the side points allow you to carry them through. The Leica is a combination of a cross-line laser with a 4-point laser (5 if you count where the lines cross). The points go up, down, left, and right, and the lines fan out to more than 180 degrees.
We also like the Agatec and the Topcon LC-2 for their compact size, low price, and simple functions: They're line lasers with points that go up and down. Except for one or two features, these two tools are identical.
Greg Burnet is a remodeling contractor in Berwyn, Ill.
Beams are created by laser diodes and projected through lenses that shape them into dots or lines. In low to moderately priced tools, such as this Topcon LC-4X (left), the diodes are housed in a pendulum. The pendulum swings from gimbals and uses gravity to bring itself to level. In higher-priced tools, such as rotary lasers and this PLS HVL 100 (right), the diodes are housed in an assembly that is leveled by servo motors. Unlike pendulums, servo motors don't swing when the floor shakes, so they can maintain a steadier line.